Research Interests

We want to increase our understanding of moss growth dynamics to include how plants respond to different evaporative conditions, how different types of moss grow, what conditions are best for the fixation of carbon dioxide from the atmosphere and growth through the synthesis of organic matter.

These developments in moss physiology will be integrated with local weather conditions in models of moss growth that can be applied across large areas to predict periods of plant growth. We will carry out laboratory experiments in which moss growth is manipulated, monitored and measured, using isotope labels and growth responses under different temperature, humidity and drying regimes. We will work on moss species that grow in a range of habitats from wet bog Sphagnums, through hummock forming Polytrichales to desiccation tolerant Syntrichia.

At the field scale, the same mosses will be monitored in their natural environment, testing how the experimentally determined dynamics apply within an ecologically relevant setting. The combination of lab and field measurements will firstly allow us to determine the controls on moss organic matter 18O composition as climatic conditions vary. Secondly, remote sensing field measurements will be made from a distance of several metres using newly developed LIFT (laser induced fluorescence transient) technology. By understanding the link between moss growth dynamics and photosynthetic activation over this larger spatial scale we will establish a baseline that will allow remote sensing methodologies, such as measurements from aeroplanes and satellites, to be used to monitor moss performance in the future.

The overall aim of the project is to establish whether the recent observed rate and pattern of climate change on the Antarctic Peninsula is outside the range of natural climate variability for the late Holocene. See project website for more information and our blog: http://geography.exeter.ac.uk/antarctica/.

Project overview:

We are developing palaeoclimate records from cores of peat from moss banks, which occur throughout the western areas of the Antarctic Peninsula. We will derive multi-proxy palaeoclimate records based on stable isotopes, testate amoebae, moss growth and degree of decay from the deepest moss banks on the Antarctic Peninsula. Target locations are distributed across the observed gradient in rates of late 20th century temperature change in order to reconstruct spatial patterns of change as well as temporal variability. Modern moss samples from the region, precipitation data, instrumental climate data and cellulose isotope records will help us understand cellulose isotope-climate relationships for the region. Testate amoebae assemblages in both modern and fossil samples will also be analysed to develop independent records of hydrological change. Moss morphology will provide supplementary data on past temperatures, and we will also test whether plant growth rates and phenology have responded to recent climate change on the Antarctic Peninsula. We aim to reconstruct climate variability for the past c. 5000 years from the stable isotope, peat humification, testate amoebae and moss morphology records and then compare and integrate the records with existing and new ice core, lake sediment and marine records to improve understanding of regional climate change and its relationship with global climate variability and external drivers.